Exams
Wisconsin DNR’s Operator Certification program will be hosting in-person paper exams coordinated and facilitated by Wisconsin DNR staff in 2025.
Exams will be held approximately four times a month for four months of the year. All 2025 exam dates and locations are listed in the table below and are available on each exam application form.
Exam application forms can be found by selecting the Exam Applications tab.
Upcoming exam sessions
| Exam Date | Exam Location | Exam Application Postmark Deadline |
|---|---|---|
| 7/14/2025 | Rice Lake | 6/16/2025 |
| 7/15/2025 | Plover | 6/16/2025 |
| 7/16/2025 | Waukesha | 6/16/2025 |
| 7/17/2025 | Fennimore | 6/16/2025 |
| 10/10/2025 | Madison | 9/16/2025 |
| 10/14/2025* | La Crosse | 9/16/2025 |
| 10/15/2025 | Rhinelander | 9/16/2025 |
| 10/16/2025 | Green Bay | 9/16/2025 |
*Denotes date is a pre-conference session. Pre-conference sessions are open to all applicants.
Please note however that private water operators (pump installers, water well drillers, heat exchange drillers) will be given preference for the exam session on 1/8/2025.
Ch. NR 114, 146, 499, and 524 Wis. Adm. Code require an individual to pass one or more exams in order to become a certified operator or license holder. these exams are provided on paper in-person by Wisconsin DNR staff throughout the year in different locations throughout the state.
All exams are multiple choice, with the only exception being the Wastewater - Unique (Subclass U) exam, which is a short-answer exam completed on paper.
Each exam day has two three-hour sessions. You are allowed the full three hours to take as many exams as you want. If you are considering taking multiple exams in one session, please consider your own test-taking speed and the number of questions in each exam.
Exam results letters are provided by mail to the mailing address provided on your application form. Results are mailed within 2-4 weeks of exam day.
Additional information, including study guides, can be found under each program's certification page. Tabs linking to each page can be found on the upper righthand side of the Exams page.
ADA & Hardship Requests
If an exam applicant requires ADA accommodations or any order legitimate, documented reason for being unable to complete an exam at a larger-group exam session, please contact the Operator Certification coordinator to request a one-person session at DNROpCert@wisconsin.gov with the subject line "Hardship exam session request - [YOUR LAST NAME]".
Each exam day has two three-hour sessions beginning at 9am and 1pm. You are allowed the full three hours to take as many exams as you want. If you are considering taking multiple exams in one session, please consider your own test-taking speed and the number of questions in each exam.
- Wastewater – General: 50 questions
- Wastewater - Suspended Growth Processes: 50 questions
- Wastewater - Attached-Growth Processes: 25 questions
- Wastewater – Recirculating Media Filters: 25 questions
- Wastewater – Ponds, Lagoons, and Natural Systems: 50 questions
- Wastewater – Anaerobic Treatment of Liquid Waste: 25 questions
- Wastewater – Solids Separation: 50 questions
- Wastewater – Biological Solids/Sludge: 50 questions
- Wastewater – Disinfection: 50 questions
- Wastewater - Laboratory: 50 questions
- Wastewater – Total Nitrogen: 25 questions
- Wastewater – Total Phosphorus: 50 questions
- Wastewater - Sanitary Sewer Collection System: 50 questions
- Wastewater – Advanced: 100 questions
- Municipal Waterworks – Distribution: 40 questions
- Municipal Waterworks – Groundwater: 40 questions
- Municipal Waterworks – Iron Removal: 40 questions
- Municipal Waterworks – Lime Softening: 40 questions
- Municipal Waterworks – Surface Water: 80 questions
- Municipal Waterworks – VOC Removal: 40 questions
- Municipal Waterworks – Zeolite Softening: 40 questions
- Small Water System – Water System General Operation: 40 questions
- Septage – Septage Operator Grade L: 40 questions
- Septage - Septage Operator Grade T: 40 questions
- Septage – Septage Master Operator Grade L: 25 questions
- Septage - Septage Master Operator Grade T: 40 questions
- Solid Waste – Site Operator: 50 questions
- Solid Waste - Facility Manager: 50 questions
- Private Water - Pump Installer: 100 questions
- Private Water - Water Well Driller: 100 questions
- Private Water – Heat Exchange Driller: 80 questions
The Operator Certification program facilitates three exams for the Private Water section of the Drinking Water and Groundwater program:
- Pump Installer
- Water Well Driller
- Heat Exchange Driller
Private Water Supply exams are "open code." Clean copies of NR 146, NR 811, and NR 812 are provided to exam registrants by Wisconsin DNR staff. No other open-book references are allowed. Failure to follow these requirements will result in forfeiture of the scheduled exam and fees.
The reference code booklet will be provided for you on the day of the exam by department staff when checking in for your exam. Booklets will be returned to department staff when turning in the exam.
Pump Installer Applicants
Pump Installer exam applicants can submit a DNR exam application and fee via mail as desired. Applications can be under the "Exam Applications" tab.
Driller Applicants
Water Well Driller and Heat Exchange Driller exam applicants must request an application by emailing DNRDGLicensing@wisconsin.gov. After eligibility review and approval, the exam application will be provided to the applicant for completion and submittal via mail.
Exam Application
How long does the application process take once I mail my exam application?
The application process can take 2-3 weeks, from the day you put your exam application form and fee in the mail to the day you receive your exam confirmation letter in the mail. If your exam application is submitted to DNR incorrectly it will be returned to you by mail with requests for how to correct the item(s) and resubmit the application form.
How should I list my name on the exam application?
Your name should be an exact match to the photo ID you will be providing to Wisconsin DNR staff on exam day.
What information is required on the exam application form?
The required fields on your exam application form section 1 are bolded and underlined. these include full name as it appears on your photo ID, mailing address, email address, work phone, and cell/home phone. You must also submit your Social Security number on page 3. For Municipal Waterworks or Small Water System (OTM/NN) exams, a signature and date certifying the possession of a high school diploma or GED is also required.
Why is my Social Security number required?
Wisconsin State Statutes 299.08(1), 29.024(2r)(a), and 299.07(1) require that the Operator Certification program submit an exam applicant or certified operator's Social Security number to the Wisconsin Department of Revenue, Department of Workforce Development to ensure that the exam applicant or operator does not have any outstanding taxes or child support payments. Your Social Security number is securely stored and any documentation with your submitted number is either redacted or destroyed. Based on these state statutes, an exam applicant cannot receive exam scores, apply exam results, or renew their certification if they do not provide their Social Security number. Any exam results or certification renewal will be withheld or will not be processed until the information is provided. If you submit an exam application without your Social Security number it will be returned to you by mail with request to provide the number accordingly.
How do I request a receipt for payment of my DNR exam fees?
Receipt for DNR payment can be requested by emailing DNROpCert@wisconsin.gov with a subject line of DNR Exam Fee Receipt Request - [Last Name]. Please include your full name, your DNR certification number if you know it, and the DNR exam fee amount you paid. the Operator Certification program will provide a PDF receipt via email.
Exam Day
When should I arrive for my exam?
Exam session check-in and instructions begin 15 minutes before the session start time. Wisconsin DNR staff recommend arriving at your testing location a minimum of 15 minutes before the start of your exam session.
What should I bring with me for exam day?
Exam takers should bring photo ID (ex. driver's license), #2 pencil, and a basic calculator. You may not use your cell phone as a calculator. You may also have a beverage during the exam. You do not need to bring or present your exam confirmation letter.
All municipal waterworks, small water system (OTM/NN), wastewater, landfill, and septage exams are closed book exams. Any exam study materials may not be used during the exam.
All pump installer, water well driller, and heat exchange driller exams are open code exams. Clean, unmarked copies of NR 146, NR 811, and NR 812 are provided to exam registrants by the Wisconsin DNR staff. these codes will be returned to Wisconsin DNR staff when turning in your exam.
Exam Confirmation Letters And Exam Results Letters
I did not receive an exam confirmation letter, am I registered?
If you did not receive an exam confirmation letter, please email DNROpCert@wisconsin.gov to check if you are registered or not.
When will my exam results be processed by the DNR?
The Operator Certification program will process your exam results and mail exam results letters within 2-4 weeks of your exam date.
I did not receive my exam results letter. Where can I see my results?
If you did not receive your exam results letter within the timeframe stated above, please email DNROpCert@wisconsin.gov. You can also check the Operator Certification Lookup page to see a list of your certifications
Retaking an Exam
How do I retake an exam that I did not pass?
To retake an exam please resubmit an exam application form and fee to register for an upcoming exam session.
Exam application forms and fees may only be submitted by mail and must be postmarked no later than four weeks prior to the requested exam date.
Exam application fees can be paid for by check, money order, or cash. Please write all checks to "Wisconsin DNR". Submit completed exam application and fee(s) to the mailing address below. the Operator Certification program will review and process complete applications within 10 business days of receipt.
Wisconsin DNR
Operator Certification EA/7
PO Box 7921
Madison, WI 53707-7921
Upon receipt, approval, and processing of your exam application, the Operator Certification program will mail you an exam confirmation letter noting the address of the exam location and what to bring on exam day. Exam confirmation and exam results letters will be mailed to the address you provide on the exam application.
- Wastewater Operator Certification Exam Application (3400-837)
- Municipal Waterworks Operator Certification Exam Application (3400-838)
- Small Water System Operator Certification Exam Application (3400-839)
- Solid Waste Disposal Facility Operator Certification Exam Application (3400-840)
- Septage Service Operator Certification Exam Application (3400-841)
- Pump Installer Personal License Exam Application (3400-843)
Renew Online
You can now renew your wastewater, municipal waterworks, and small water system certifications online through the Environmental Licensing and Certification Online Renewal Portal.